 The GNSSA technique has enabled researchers to collect time series of seafloor crustal deformation data from the Nankaitrof, Tsagemitrof and Japan Trench. These data are being used to study seismological phenomena such as the Nankaitrof, Tsagemitrof and Japan Trench, which are important areas for geodesy and seismology. The data can also be compared with other geophysical datasets to gain further insight into these regions. This article was authored by Yusuke Yokota, Tadashi Ishikawa and Shonichi Watanabe.